Still no word back from
WoodMaxx.
I took the mower off the tractor, and disconnected the PTO. This led to me finding that the gear box was almost completely loose from the mower. There are 4 bolts (M12) that come up from inside the mower compartment and hold the gear box down, two were missing (NOT broken off) and two were loose. This would obviously effect belt alignment and tension, but it is worth noting that the movement allowed by this looseness is separate from the play in the driveshaft. There is still play in the driveshaft as well, without the gearbox moving. It basically seems like this thing was rattling itself apart inn 3 ours of use.
I know that manuals call for checking the tightness of nuts/bolts, etc. at crazy intervals, but this seems. bit over the top. I wasn't supposed to take the thing apart to check every fastener, right?